var number_of_image;
image_list = new Array();

function setNumberOfImages(number) {

	number_of_image = number;

}

function setImageList(temp_list) {

	image_list = temp_list;

}

function imageItem(image_location) {
	
	this.image_item = new Image();
	this.image_item.src = "images/" + image_location;
	
}

function get_ImageItemLocation(imageObj) {
	
	return imageObj.image_item.src

}

function generate(x, y) {
	
	var range = y - x + 1;
	return Math.floor(Math.random() * range) + x;
	
}

function getImage() {
	
	image_index = generate(0, number_of_image-1);
	var new_image = get_ImageItemLocation(image_list[image_index]);
	return new_image;
	
}

function setImage() {
	
	if (number_of_image > 0) {
		
		var new_image = getImage();
		document['mainimage'].src = new_image;
		
	}

}